A copper wire having a mass of 2.196 g was allowed to react with an excess of sulfur. The excess sulfur was then burned, yielding SO₂ gas. The mass of the copper sulfide produced was 2.748 g. (b) What is its empirical formula?

Video transcript

Hey everyone, welcome back. We're asked to provide the empirical formula for a substance consisting of 1.78g of copper and 2.22g of selenium first. Let's go ahead and convert our grams into moles. Starting off with 1.78 g of copper. We're going to use coppers atomic mass of 63. g per one mole. And when we calculate this out, we end up with a value of 0. mol of copper. Moving on to selenium, we have 2.22g of selenium And we know that selenium is atomic mass is 78.96 g of selenium per one mole. And when we calculate this out, we end up with a total of 0.02, a mole of selenium. And now all we need to do is divide both of our values by the least amount of moles. And in this case since both of our values are 0.028, All we need to do is divide them both by 0.028 which gets us to one of copper and one of selenium. So our empirical formula is going to be C U S E. So I hope this made sense and let us know if you have any questions